Circuits and Systems Society

Description by Tor Sverre Lande: The importance of microelectronics in biomedical devices is increasing. At ISCAS 2004 in Vancouver this fact was illustrated through several papers on retinal implants. In the BioCAS-L1 session two papers (BIO-L1.1 and BIO-L1.3) were given on an implantable prosthetic retina with inductive signal and power transfer. The visual scene is transferred through the power link and the retinal nerve cells are stimulated. An even braver approach is adopted in paper BIO-L2.5 exploring solar cells integrated with microelectronics for artificial retinal prostheses.

References: Proceedings of the 2004 International Symposium on Circuits and Systems (ISCAS 2004). Sorry, at the time of the edition of this news issue, these proceedings were not yet available on IEEE Xplore.

Communicated by the Technical Committee on Biomedical Circuits and Systems

2. Femptoampere Current Mode Circuits

Description by the authors: Circuit techniques are introduced to handle and process currents down to femto-amperes. Current mirrors, splitters, oscillators and filters are built, and noise and mismatch is characterized. Very useful for ultra-low power circuit design and compact very low speed circuits.

Reference: Bernabé Linares-Barranco and Teresa Serrano-Gotarredona, "On the Design and Characterization of Femtoampere Current-Mode Circuits," IEEE Journal of Solid-State Circuits, vol. 38, No. 8, pp. 1353-1363, August 2003.

Communicated by the Technical Committee on Neural Systems and Applications and the Technical Committee on Sensory Systems

3. Color Based Object Recognition on a Chip

Description by Ralph Etienne-Cummings: A complete imager-to-recognition system is presented. The imager generates a color image in RGB space, which is transformed to HSI space. Over a prescribed region of the image, an HSI histogram is constructed. The histogram becomes a template for object(s) in the region. This template can be stored in focal plane memory (learning phase), or it can be directly used to compare with already stored templates (recognition phase). The best matched template is indicated by the chip. This chip has a number of applications in machine/robot vision, particularly when the ambient lighting is controlled.

Reference: R. Etienne-Cummings, P. Pouliquen and M. A. Lewis, “A Vision Chip for Color Segmentation and Object Recognition,” EURASIP J. Applied Signal Processing, Vol. 2003, No. 7, pp. 703-712, June 2003. (BEST PAPER 2003)

Communicated by the Technical Committee on Neural Systems and Applications

4. Fault Diagnosis and Fault Tolerance in Networks and Systems

Description by Krishnaiya Thulasiraman: The following references give a good view of some of the recent trends in this field for the context of telecommunication networks and systems applications. The first reference discusses design of redundant trees for reliable broadcast in the presence of a single node/edge failure. The second reference discusses construction of protection sub-networks and how they can be used for loop-back recovery in optical networks. The third and the fourth references discuss development of algebraic techniques to construct redundant system implementations that permit error correction to be performed non-concurrently.

References:

1. M. Medard, S.G.Finn, R.A Barry and R.G. Gallager, “Redundant Trees for Preplanned Recovery in Arbitrary Vertex-Redundant or Edge-Redundant Graphs”, IEEE/ACM Transactions on Networking, Vol. 7 , pp. 641-652, 1999.

2. M.Medard, R.A.Barry, S.G.Finn, W.He and S.S.Lumetta, “ Generalized Loop-Back Recovery in Optical Mesh Networks”, IEEE/ACM Transactions on Networking, Vol. 10 , pp.153-164, 2002

3.C.N. Hadjicostis, Coding Approaches to Fault Tolerance in Combinational and Dynamic Systems , Kluwer Academic Publishers, 2002.

4. C.N.Hadjicostis, “Non-concurrent Error Detection and Correction in Fault Tolerant Discrete Time LTI Dynamic Systems”, IEEE Transactions on Circuits and Systems-I, Vol. 50, No.1, pp.45-55, January 2003.

Communicated by the Technical Committee on Graph Theory and Applications.

5. Chaos-based Frequency Modulated Signals

Description by Gian Mario Maggio: This work addresses the problem of generating constant-envelope wideband (CEW) signals, for which applications are emerging in digital/power electronics to synthesize timing signals favoring electromagnetic compliance (EMC). A flexible generation technique consists of driving an FM (frequency modulation) modulator with random or chaotic sequences. The mathematical tools for predicting the spectral properties of random-FM and chaotic-FM CEW signals are introduced and quantitative results presented.

Reference:S. Callegari, R. Rovatti, G. Setti, “Spectral Properties of Chaos-Based FM Signals: Theory and Simulation Results”, IEEE Transactions on Circuits and Systems - Part I, Vol. 50, n. 1, pp. 3-13, January 2003 (2004 CASS Darlington Award)

Communicated by the Technical Committee on Nonlinear Circuits and Systems